Effects of Textural Properties on the Response of a SnO2-Based Gas Sensor for the Detection of Chemical Warfare Agents

The sensing behavior of SnO2-based thick film gas sensors in a flow system in the presence of a very low concentration (ppb level) of chemical agent simulants such as acetonitrile, dipropylene glycol methyl ether (DPGME), dimethyl methylphosphonate (DMMP), and dichloromethane (DCM) was investigated. Commercial SnO2 [SnO2(C)] and nano-SnO2 prepared by the precipitation method [SnO2(P)] were used to prepare the SnO2 sensor in this study. In the case of DCM and acetonitrile, the SnO2(P) sensor showed higher sensor response as compared with the SnO2(C) sensors. In the case of DMMP and DPGME, however, the SnO2(C) sensor showed higher responses than those of the SnO2(P) sensors. In particular, the response of the SnO2(P) sensor increased as the calcination temperature increased from 400 °C to 800 °C. These results can be explained by the fact that the response of the SnO2-based gas sensor depends on the textural properties of tin oxide and the molecular size of the chemical agent simulant in the detection of the simulant gases (0.1–0.5 ppm)

Improving the SO2 absorption rate of CeFeMg-based sorbent promoted with titanium promoter

To improve the poor SO2 absorption rate of CeFeMgTi sorbent with high sulfur removal capacity and fast regeneration, a new sorbent, CeFeMgTi-sol was prepared by the modified co-precipitation method and tested in a packed bed reactor at RFCC conditions (sulfation of MgO to MgSO4 in the presence of low concentration of SO2 at 973 K, regeneration of MgSO4 to MgO and H2S in the presence of H-2 at 803 K). The CeFeMgTi-sol sorbent showed excellent SO2 absorption and sulfur removal capacity (46.2 sulfur g/g absorbentx100). It was found that the SO2 absorption rates were related to the structure of the Mg and Ti and the textural properties such as surface area and pore volume. In the case of the fresh state of CeFeMgTi sorbent, CeO2, MgO and MgTiO3 structures were observed. But the new CeFeMgTisol sorbent before SO2 absorption, showed a separated MgO and TiO2 peak only. These differences in the sorption rates were discussed by the difference in the XRD pattern, surface area and pore volume.FALS

Fabrication and Optical Properties of Erbium-Doped Polymer Films

The crosslinked, fluorinated, patterned and erbium (Er 3+) doped polymer films were fabricated by UV-curing after a simple spin-coating. Er 3+-doped solutions containing Irgacure 819 used as a radical-type photoinitiator were prepared using erbium (III) trifluoromethane sulfonate as an erbium source, 2,2,3,3,4,4,5,5-octafluoropentyl acrylate as a fluorinated monomer, trimethylolpropane triacrylate and Ebecyl 810 resin as a crosslinking agent with various weight ratios. The fluorinated polymer films fabricated in this study showed the excellent transmission property more than 80% over visible and NIR region, and high thermal decomposition temperature about 310°C sufficient for optical device applications. From these results, the Er 3+-doped polymer films developed in this study could be applied to optical telecommunication devices. Copyright © Taylor & Francis Group, LLC.

Investigation of Co–Fe–Al Catalysts for High-Calorific Synthetic Natural Gas Production: Pilot-Scale Synthesis of Catalysts

Co–Fe–Al catalysts prepared using coprecipitation at laboratory scale were investigated and extended to pilot scale for high-calorific synthetic natural gas. The Co–Fe–Al catalysts with different metal loadings were analyzed using BET, XRD, H2-TPR, and FT-IR. An increase in the metal loading of the Co–Fe–Al catalysts showed low spinel phase ratio, leading to an improvement in reducibility. Among the catalysts, 40CFAl catalyst prepared at laboratory scale afforded the highest C2–C4 hydrocarbon time yield, and this catalyst was successfully reproduced at the pilot scale. The pelletized catalyst prepared at pilot scale showed high CO conversion (87.6%), high light hydrocarbon selectivity (CH4 59.3% and C2–C4 18.8%), and low byproduct amounts (C5+: 4.1% and CO2: 17.8%) under optimum conditions (space velocity: 4000 mL/g/h, 350 °C, and 20 bar)

Investigation of Co–Fe–Al Catalysts for High-Calorific Synthetic Natural Gas Production: Pilot-Scale Synthesis of Catalysts

Co–Fe–Al catalysts prepared using coprecipitation at laboratory scale were investigated and extended to pilot scale for high-calorific synthetic natural gas. The Co–Fe–Al catalysts with different metal loadings were analyzed using BET, XRD, H2-TPR, and FT-IR. An increase in the metal loading of the Co–Fe–Al catalysts showed low spinel phase ratio, leading to an improvement in reducibility. Among the catalysts, 40CFAl catalyst prepared at laboratory scale afforded the highest C2–C4 hydrocarbon time yield, and this catalyst was successfully reproduced at the pilot scale. The pelletized catalyst prepared at pilot scale showed high CO conversion (87.6%), high light hydrocarbon selectivity (CH4 59.3% and C2–C4 18.8%), and low byproduct amounts (C5+: 4.1% and CO2: 17.8%) under optimum conditions (space velocity: 4000 mL/g/h, 350 °C, and 20 bar)

The transport of a reversible proton pump antagonist, 5, 6-dimethyl-2-(4Fluorophenylamino)-4-(1-methyl-1,2,3, 4-tetrahydroisoquinoline2-yl) pyrimidine hydrochloride (YH1885), across caco-2 cell monolayers. Drug Metab Dispos

This paper is available online at http://dmd.aspetjournals.org ABSTRACT: 5,6-Dimethyl-2-(4-fluorophenylamino)-4-(1-methyl-1,2,3,4-tetrahydroisoquinoline-2-yl) pyrimidine hydrochloride (YH1885) is under development as a novel acid pump antagonist by Yuhan Research Center. Previous studies have suggested that the AUC and C max of orally dosed YH1885 are dose-dependent in the range of 2 to 500 mg/kg. The objective of the present study was to investigate the absorption mechanism of YH1885 using a human colon carcinoma cell line, Caco-2. The cells were grown to confluency on a permeable polycarbonate membrane insert to permit loading of YH1885 on either the apical or basolateral side of the cell monolayer. The flux across the monolayer from the apical to basolateral side was 3 to 5 times greater than that from the basolateral to apical side. The uptake of YH1885 into the Caco-2 cell monolayer was saturable and appeared to be mediated by a high-affinity transporter, with an apparent K m of 1.47 ؎ 0.21 M and a V max of 25.14 ؎ 1.16 pmol/cm 2 /40 s. The apical to basolateral transport across the monolayer was Na ؉ -independent, H ؉ -sensitive, and energydependent. The transport was inhibited significantly by the presence of structural analogs of YH1885 (e.g., YH957, YH1070, and YH1041), some pyrimidine nucleobases (uracil and 5-methyluracil), and nucleobase transport inhibitors (e.g., papaverine, dipyridamole, and phloridzin). These results demonstrate that the apical to basolateral transport of YH1885 across the Caco-2 cell monolayer is partially mediated by a nucleobase transport system, which exhibits high-affinity and energy-dependent properties for YH1885. Saturation of this transport system, in addition to the limited solubility of YH1885 (i.e., ϳ5.3 M), appears to contribute to the dose-dependent bioavailability of the drug

Improving the Stability of Ru-Doped Ni-Based Catalysts for Steam Methane Reforming during Daily Startup and Shutdown Operation

In this study, a Ru-doped Ni pellet-type catalyst was prepared to produce hydrogen via steam methane reforming (SMR). A small amount of Ru addition on the Ni catalyst improved Ni dispersion, thus affording a higher catalytic activity than that of the Ni catalyst. During the daily startup and shutdown (DSS) operations, the CH4 conversion of Ni catalysts significantly decreased because of Ni metal oxidation to NiAl2O4, which is not reduced completely at 700 °C. Conversely, the oxidized Ni species in the Ru–Ni catalyst can be reduced under SMR conditions because of H2 spillover from the surface of Ru onto the surface of Ni. Consequently, the addition of a small quantity of Ru to the Ni catalyst can improve the catalytic activity and stability during the DSS operation